240 General: New (to me) 1980 Volvo 244

[Laird Scooby]

Originally Posted by Othen

Ah, cunning, so the link to terminal 85 works like a NAND gate, I had not appreciated that and it is quite clever. Once I have the existing setup apart I think I might be able to design a good working system around or and your design.


Alan

That's one way of looking at it Alan but overcomplicating it somewhat.

The relay coil takes something in the region of 40mA so is about 300 Ohms. The headlight filament take 5A ish so is 2.4 Ohms ish.

At 40mA, the relay will develop 300 x 0.04 = 12V and the main beam filament, 2.4 x 0.040 = 0.096V so the relay coil will operate if fed from terminal 86 but as soon as the main beam is powered up with +12V, you have +12V on BOTH sides of the relay coil - net potential difference = 0V, therefore the relay coil doesn't operate.

It's a classic example of using a backfeed to control what you want to happen. Usually in car electrics, backfeeds cause all kinds of trouble!

If you've ever had to diagnose a fault on a two-switch lighting circuit in a house, for example the landing/hall lights with a switch top and bottom of the stairs and someone else has been there before you and interposed a N with a switched L (because the red ident has been lost from the black switched live) you'll know all about backfeeds on AC - cars aren't wildly different but can be useful if you know they are there, or an absolute nightmare to trace if they're causing a problem!

That's why i included the 1N400x diode as a blocking diode to prevent backfeeds from main beam through the foglight relay.

It's a pretty common automotive circuit, more common is to take terminal 85 to earth but this is slightly more sophisticated to ensure the fogs don't work with main beam.

As for the gearbox, you might like to spend some time lurking on th 7/9xx forum in the For Sale section, there are a few 940s being broken, some auto so you should have your pick of boxes. Don't get one with an "E" suffix as that denotes electronic control, off the top of my head i can't remember if the lock-up torque converter needs a bit of electrickery to make it work but a straightforward AW70/71 with overdrive 4th would still be a big improvement.
I'm not sure what else you'd need but i suppose a lot depends on what box you currently have (BW65 perhaps?) and what would be easiest to swap.

It's one of those jobs that will be nice to do when you've got the time and weather to do it over a weekend and take it easy doing it.

[Bugjam1999]

One question about gearboxes- Did the later auto boxes ever come with a cable drive to drive the speedo?

The speedo currently fitted is cable driven, Volvo swapped to an electronic speedo with a pickup in the diff cover in... 1982? 1984?

If you wanted to (and people have done so, to fit later engine and gearbox combinations to early cars, notably turboed engines) you could swap the rear axle for one with a speedo sensor in the diff cover, then build a hybrid instrument cluster out of the early ‘shell’ with a later electronic speedo inside. This would mean that a later gearbox with no cable drive pickup could be fitted. I imagine that might be a bit too much work for a swap to a 4-speedo auto gearbox.

Cheers

[Laird Scooby]

Originally Posted by Bugjam1999

One question about gearboxes- Did the later auto boxes ever come with a cable drive to drive the speedo?

The speedo currently fitted is cable driven, Volvo swapped to an electronic speedo with a pickup in the diff cover in... 1982? 1984?

If you wanted to (and people have done so, to fit later engine and gearbox combinations to early cars, notably turboed engines) you could swap the rear axle for one with a speedo sensor in the diff cover, then build a hybrid instrument cluster out of the early ‘shell’ with a later electronic speedo inside. This would mean that a later gearbox with no cable drive pickup could be fitted. I imagine that might be a bit too much work for a swap to a 4-speedo auto gearbox.

Cheers

Not as far as i'm aware, hadn't thought of that to be fair. What about swapping gearbox extension housings to provide the speedo drive?



That's an AW70 extension housing and you can see where the speedo drive would be, fairly sure it should be possible to swap the speedo drive and extension housing, do the bush and seal at the same time (which is why that one was off) and fit a new propshaft centre bearing too.

A hybrid speedo and a later diff with the sensor would also work, i'm sure there are other cars with cable driven speedos using the later AW or ZF boxes, just can't think of any at the moment but should be feasible to swap the extension housings.

[Othen]

Originally Posted by Laird Scooby

That's one way of looking at it Alan but overcomplicating it somewhat.

The relay coil takes something in the region of 40mA so is about 300 Ohms. The headlight filament take 5A ish so is 2.4 Ohms ish.

At 40mA, the relay will develop 300 x 0.04 = 12V and the main beam filament, 2.4 x 0.040 = 0.096V so the relay coil will operate if fed from terminal 86 but as soon as the main beam is powered up with +12V, you have +12V on BOTH sides of the relay coil - net potential difference = 0V, therefore the relay coil doesn't operate.

It's a classic example of using a backfeed to control what you want to happen. Usually in car electrics, backfeeds cause all kinds of trouble!

If you've ever had to diagnose a fault on a two-switch lighting circuit in a house, for example the landing/hall lights with a switch top and bottom of the stairs and someone else has been there before you and interposed a N with a switched L (because the red ident has been lost from the black switched live) you'll know all about backfeeds on AC - cars aren't wildly different but can be useful if you know they are there, or an absolute nightmare to trace if they're causing a problem!

That's why i included the 1N400x diode as a blocking diode to prevent backfeeds from main beam through the foglight relay.

It's a pretty common automotive circuit, more common is to take terminal 85 to earth but this is slightly more sophisticated to ensure the fogs don't work with main beam.

As for the gearbox, you might like to spend some time lurking on th 7/9xx forum in the For Sale section, there are a few 940s being broken, some auto so you should have your pick of boxes. Don't get one with an "E" suffix as that denotes electronic control, off the top of my head i can't remember if the lock-up torque converter needs a bit of electrickery to make it work but a straightforward AW70/71 with overdrive 4th would still be a big improvement.
I'm not sure what else you'd need but i suppose a lot depends on what box you currently have (BW65 perhaps?) and what would be easiest to swap.

It's one of those jobs that will be nice to do when you've got the time and weather to do it over a weekend and take it easy doing it.

Thank you for that explanation Dave, very clever.

I think the gearbox will become a longer term issue, perhaps one for next year. I'll do some research this year and come up with a plan. I suppose the option of changing to a 4 speed manual (as per the earlier offer) would be easiest, or maybe a 5 speeder from a 240, but I'm still attracted by the idea of a 4 speed auto. Do you think this might be the right box:

https://www.ebay.co.uk/itm/VOLVO-240...97.m4902.l9144

... much less expensive that I thought it might be.

Alan

[Othen]

Originally Posted by Bugjam1999

One question about gearboxes- Did the later auto boxes ever come with a cable drive to drive the speedo?

The speedo currently fitted is cable driven, Volvo swapped to an electronic speedo with a pickup in the diff cover in... 1982? 1984?

If you wanted to (and people have done so, to fit later engine and gearbox combinations to early cars, notably turboed engines) you could swap the rear axle for one with a speedo sensor in the diff cover, then build a hybrid instrument cluster out of the early ‘shell’ with a later electronic speedo inside. This would mean that a later gearbox with no cable drive pickup could be fitted. I imagine that might be a bit too much work for a swap to a 4-speedo auto gearbox.

Cheers

Fascinating Bugjam... I was just trying to imagine the Royal Barge with another 100 HP or so :-)

A question for you: I think you said you had converted your 240 4 speed manual to a 5 speeder. Was that a difficult job? I'm not ruling out a change to a manual gearbox, but it strikes me that if I went that way it might make sense to find a 5 speeder.

Best wishes,

Alan

[Bugjam1999]

Originally Posted by Othen

Fascinating Bugjam... I was just trying to imagine the Royal Barge with another 100 HP or so :-)

A question for you: I think you said you had converted your 240 4 speed manual to a 5 speeder. Was that a difficult job? I'm not ruling out a change to a manual gearbox, but it strikes me that if I went that way it might make sense to find a 5 speeder.

Best wishes,

Alan

Not hard, no- but first a quick overview of manual gearboxes, since you (sort of) asked.

So when the 244 and 245 were launched in the U.K., they came with an M45 4-speed gearbox, which has a cable drive output to drive the speedo.

In 1982 (1984?) Volvo swapped to an electronic pickup in the rear axle to drive the speedo, combined with a dashboard revamp to the later style seen in cars from 1982 to the end of the run in 1993. These cars got an m47 5-speed gearbox that doesn’t have a speedo drive.

5-speed options with a cable drive do exist however - for a very small window of time it was possible to order a 5-speed as a factory upgrade when buying a new early car and some cars during the cross over year had a later style speedo that was actually driven by a cable drive. This means there are a tiny number of M47 gearboxes out there that have a speedo drive.

There is also an m46 gearbox, which is an m45 with an overdrive unit bolted to the back of it. I’m not sure why an upgrade would have been an m46 or an m47, perhaps it depended on trim level (ie an early glt) or the year - someone will know.

So, if you decide to go for 5 speeds, you’re looking for either an M46 from a 244/245, which means it’ll have a speedo drive- this combination was also fitted to early 740s, which means they don’t have a speedo drive output as a 740 never had a cable drive speedo. You’ll also need the propshaft.

The other option is an M47 with a speedo drive, again with its propshaft as they’re different to the propshaft fitted with a later M47.

Of course, both of the above are getting fairly rare. I was lucky enough to find an m47 with a cable drive which is what I swapped into my 1978. In terms of the difficulty of the swap, it involves pulling the engine and gearbox out of course, but it isn’t too difficult and apart from the engine hoist only requires normal tools - I managed it on my own over a day and a bit. I explain it with photos in my project thread, linked below.

https://www.volvoforums.org.uk/showthread.php?t=268976

A 240 with an extra 100bhp does make quite a difference- I turbo swapped my 240 back in 2015 and have enjoyed driving the car since then. I really need to update my project thread for that car, but here’s the link.

https://www.volvoforums.org.uk/showthread.php?t=228229

Cheers

[Othen]

Originally Posted by Bugjam1999

Not hard, no- but first a quick overview of manual gearboxes, since you (sort of) asked.

So when the 244 and 245 were launched in the U.K., they came with an M45 4-speed gearbox, which has a cable drive output to drive the speedo.

In 1982 (1984?) Volvo swapped to an electronic pickup in the rear axle to drive the speedo, combined with a dashboard revamp to the later style seen in cars from 1982 to the end of the run in 1993. These cars got an m47 5-speed gearbox that doesn’t have a speedo drive.

5-speed options with a cable drive do exist however - for a very small window of time it was possible to order a 5-speed as a factory upgrade when buying a new early car and some cars during the cross over year had a later style speedo that was actually driven by a cable drive. This means there are a tiny number of M47 gearboxes out there that have a speedo drive.

There is also an m46 gearbox, which is an m45 with an overdrive unit bolted to the back of it. I’m not sure why an upgrade would have been an m46 or an m47, perhaps it depended on trim level (ie an early glt) or the year - someone will know.

So, if you decide to go for 5 speeds, you’re looking for either an M46 from a 244/245, which means it’ll have a speedo drive- this combination was also fitted to early 740s, which means they don’t have a speedo drive output as a 740 never had a cable drive speedo. You’ll also need the propshaft.

The other option is an M47 with a speedo drive, again with its propshaft as they’re different to the propshaft fitted with a later M47.

Of course, both of the above are getting fairly rare. I was lucky enough to find an m47 with a cable drive which is what I swapped into my 1978. In terms of the difficulty of the swap, it involves pulling the engine and gearbox out of course, but it isn’t too difficult and apart from the engine hoist only requires normal tools - I managed it on my own over a day and a bit. I explain it with photos in my project thread, linked below.

https://www.volvoforums.org.uk/showthread.php?t=268976

A 240 with an extra 100bhp does make quite a difference- I turbo swapped my 240 back in 2015 and have enjoyed driving the car since then. I really need to update my project thread for that car, but here’s the link.

https://www.volvoforums.org.uk/showthread.php?t=228229

Cheers

Excellent Bugjam, thank you so much for the potted history of Volvo 240 gearboxes - I'm learning lots about these cars :-)

I started reading the threads - marvelous - I'll finish reading this eve.

Alan

[Clifford Pope]

Fascinating thread - mostly above my level, although I did once swap an M47 in a 1993 Torslanda for a M46 (overdrive), simply because I loved overdrives.
(Incidently, the M46 is a much more robust gearbox, and in my experience will easily do more than 400,000 miles, while an M47 may well be getting clunky or noisy at 200,000 miles)

I gave the old M47 to a friend who had an earlier M45 and wanted a 5-speed.
Both swaps were absolutely straightforward bolt-on jobs, with the prop shaft from the appropriate gearbox. (The cars had axle-sensor speedos, so no problems there)
All the cars have all the captive nuts needed for all the gearbox cross-member position options.

By the way, I just mention this, although I have never heard of anyone else having this problem. The axle sensors have colour-coded wires, and have to connect the correct way round. When I once had one fail I replaced it with a known working unit from a similar-year car, plugging the connectors together and noting that the colours corresponded. It took me a lot of messing around to discover that for some bizarre reason Volvo had changed the colours over, so the speedo only worked when going backwards. I cut and re-soldered the wires in reverse positions and it worked perfectly.
(I've also once replaced a tailgate locking motor with wire colours reversed. It "worked" when tested, but in the opposite direction)

[Laird Scooby]

Originally Posted by Othen

Thank you for that explanation Dave, very clever.

I think the gearbox will become a longer term issue, perhaps one for next year. I'll do some research this year and come up with a plan. I suppose the option of changing to a 4 speed manual (as per the earlier offer) would be easiest, or maybe a 5 speeder from a 240, but I'm still attracted by the idea of a 4 speed auto. Do you think this might be the right box:

https://www.ebay.co.uk/itm/VOLVO-240...97.m4902.l9144

... much less expensive that I thought it might be.

Alan

That might be the right gearbox Alan, however the pics are a tad blurry and no close up of the ID label to know for sure. I don't suppose you happen to know what box you have at the moment?
If you have a look at this thread, i know Luke (360beast) has a few autoboxes available :

https://www.volvoforums.org.uk/showthread.php?t=287440

I doubt they'll sell quickly and i suspect he may have more in the future so worth making contact.

As a general rule of thumb, updating one autobox for another is easier than doing a manual conversion. It's not just the gearbox you have to change, the flywheel, clutch, sometimes the starter motor, pedal box (to gain a clutch pedal), centre console, gearlever (obviously! ) and a few other bits i'm sure i've forgotten.
It's not impossible but the other thing to consider is the character of the car - does it suit an auto box? Do you do much town driving? If the answer is yes to both of those then i'd suggest updating the auto - if you don't do much town driving and you feel as if the character of the car would suit a manual as well as an auto, then go for a manual conversion.

[Othen]

Originally Posted by Laird Scooby

That might be the right gearbox Alan, however the pics are a tad blurry and no close up of the ID label to know for sure. I don't suppose you happen to know what box you have at the moment?
If you have a look at this thread, i know Luke (360beast) has a few autoboxes available :

https://www.volvoforums.org.uk/showthread.php?t=287440

I doubt they'll sell quickly and i suspect he may have more in the future so worth making contact.

As a general rule of thumb, updating one autobox for another is easier than doing a manual conversion. It's not just the gearbox you have to change, the flywheel, clutch, sometimes the starter motor, pedal box (to gain a clutch pedal), centre console, gearlever (obviously! ) and a few other bits i'm sure i've forgotten.
It's not impossible but the other thing to consider is the character of the car - does it suit an auto box? Do you do much town driving? If the answer is yes to both of those then i'd suggest updating the auto - if you don't do much town driving and you feel as if the character of the car would suit a manual as well as an auto, then go for a manual conversion.

Thank you again Dave.

I’m sitting in a McDonalds waiting for the tyres to be changed to 195/65R15, which will bring it much closer to the original ride than the 50 profile tyres the PO had, I think he wanted to make it look more sporty (hence the daft roof spoiler and so on). My point is the ethos of the Royal Barge is heading back towards suiting an auto box, the way it was made. This car will be used mostly in an around town (I have a sensible modern diesel estate car for long distances, towing trailers, moving Bob’s crate, collecting motorbikes and so on), so having thought about it an auto box suits the Royal Barge much better.

The current 3 speeder works fine, and has only done 107,000 miles in 40 years, but it is a bit low geared. I’m leaning towards a 4 speed auto conversion, not this summer I think: I’m going to enjoy driving the Royal Barge a bit, but do the research and acquire the bits this year with a view to doing the work next year.

I’ll certainly make contact with Luke over the next few weeks, thank you for the lead.

I think the Royal Barge is heading in the right direction and will end up being a very nice car. I’m most happy to invest some thought, time and money on sensible improvements with a view to still owning it in 20 years and perhaps 40,000 miles time.

The acetone arrived in the mail today, so I should be able to get the roof cleaned up from the remnants of that awful roof spoiler this eve - another step on the Royal Barge’s journey.

Best wishes,

Alan